According to his business plan (embedded below, thanks to GigaOM) Falcone sees the launch happening before the third quarter of 2011, when a trial network set for Denver and Phoenix would cover 9 million. The next milestone is 100 million people to be covered by the end of 2012, 145 million by the end of 2013 and at least 260 million people in the United States by the end of 2015. (There's about 250 million wireless subscribers.)

Harbinger will have to raise billions of dollars to see this project to fruition. They don't have anyone lined up yet. GigaOM estimates it will take Harbinger $6 billion. On the subject of fundraising, they received this message from a spokesman at Harbinger:

Harbinger is in discussions with a number of companies, which we cannot disclose, that provide a variety of services and solutions, but have not finalized anything with any potential partners.

Harbinger is invested in other satellite companies (TerreStar and Leap Wireless) so he might tap them for help expanding the network, and of course Falcone is a billionaire, but there is still a lot of money to raise. And that's just the beginning.

On top of that Falcone will have to overcome:

The difficulty (and $5 billion cost) of building out a network that would cover 100 million people by the end of 2012. This stuff is complex and often takes longer than expected.

Fend off AT&T and Verizon, which are already pissed at the plan. (And because of regulation, the top two cell companies could only wholesale 25% of the available network space, if they needed it.)

Find buyers for 4G service, ranging from other phone companies to non-phone companies that want to sell mobile Internet access.